Bulb



FIG. 1 is a perspective view of a first embodiment of a bulb of the claimed design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a top elevational view thereof;

FIG. 4 is a bottom elevational view thereof;

FIG. 5 is a front elevational view thereof;

FIG. 6 is a top elevational view thereof; and,

FIG. 7 is a side cross-sectional view thereof.

The features shown in broken lines are environment only and not part of the claimed design. 

CLAIM The ornamental design for a bulb, as shown and described. 